x86 family 15 model 6 stepping 4 genuineintel ~3391 mhz

I'm using a desktop with processor "x86 family 15 model 6 stepping 4 genuineintel 3391 mhz". How does it compare to "Intel® Core 2 Duo processor T5500 (1.66GHz, 2MB L2, 667MHz FSB)"? If slower, by how much? And other aspects? Dumb, I know. I'm just trying to get some idea how a new T60/61 will run.